Method to detect and score churn in online social games

ABSTRACT

A method and a system for predicting churn of a player of an online game is described. Online engagements of a group of players of the online game are monitored during a churn prediction model training period. Online engagement scores for the group of players are computed within a periodic number of days within the churn model training period. A weighted exponential moving average of the online engagement scores of the group of players of the online game is computed during the churn model training period. The weighted exponential moving average is used to determine an online engagement threshold value of a churn prediction model for the online game. The online engagement threshold value is applied to a weighted exponential moving average of a player during an observation period to determine a churn probability of the player within a prediction period.

CROSS-REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. patent applicationSer. No. 13/436,315, filed on Mar. 30, 2012, and issued as U.S. Pat. No.8,790,168 on Jul. 29, 2014, which claims the benefit of U.S. ProvisionalPatent Application Ser. No. 61/588,589, filed Jan. 19, 2012, entitled“METHOD TO DETECT AND SCORE CHURN IN ONLINE SOCIAL GAMES”, which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to games and applications ingeneral and, in particular embodiments, to computer-implemented, onlinesocial games.

BACKGROUND

Online social games are becoming widespread. The success of an onlinesocial game depends on the number of players and how often these playersvisit the online social game. As such, the retention of online playersto visiting the online social games is an important factor towards thesuccess of the online social games.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings in which:

FIG. 1 illustrates an example embodiment of a system for implementingparticular disclosed embodiments.

FIG. 2 illustrates an example embodiment of a social network.

FIG. 3 illustrates a flow diagram of an example embodiment of a methodfor detecting and scoring churn in online social games.

FIG. 4 illustrates a flow diagram of another example embodiment of amethod for increasing retention using churn prediction in online socialgames.

FIG. 5A illustrates an example embodiment of a data flow in a system.

FIG. 5B is an example embodiment of a churn prediction server.

FIG. 6 illustrates an example embodiment of a network environment.

FIG. 7 illustrates an example embodiment of a computer systemarchitecture.

FIG. 8 is a block diagram illustrating an example of a timeline forchurn prediction.

FIG. 9 illustrates an example of a table illustrating the weightingscheme with their corresponding online engagement scores.

DETAILED DESCRIPTION

Although the present invention has been described with reference tospecific example embodiments, it will be evident that variousmodifications and changes may be made to these embodiments withoutdeparting from the broader spirit and scope of the invention.Accordingly, the specification and drawings are to be regarded in anillustrative rather than a restrictive sense.

A method and a system for predicting churn of a player of an online gameis described. Online engagements of a group of players of an online gameare monitored during a churn prediction model training period. The churnprediction model training period includes the last first number of days(e.g., last 90 days). Online engagement scores for the group of playersare computed based on a number of days the group of players has playedon the online game within a periodic number of days (e.g., a week)within the churn model training period (e.g. last 90 days). Exponentialweights are assigned to the online engagement scores so that a weight ofan online engagement score is higher when occurred more recently. Theexponential weights are used to compute a weighted exponential movingaverage of the online engagement scores of the group of players of theonline game during the churn model training period (e.g., last 90 days).The weighted exponential moving average of the online engagement scoresof the group of players of the online game is used to determine anonline engagement threshold value of a churn prediction model for theonline game. The online engagement threshold value is applied to aweighted exponential moving average of an online engagement score of aplayer during an observation period comprising the last second number ofdays (e.g., last 30 days) to determine a churn probability of the playerwithin a prediction period comprising the next third number of days(e.g., the next 30 days).

Game Networking System

FIG. 1 illustrates an example of a system for implementing variousdisclosed embodiments. In particular embodiments, system 100 comprisesplayer 101, social networking system 120 a, game networking system 120b, client system 130, and network 160. The components of system 100 canbe connected to each other in any suitable configuration, using anysuitable type of connection. The components may be connected directly orover a network 160, which may be any suitable network. For example, oneor more portions of network 160 may be an ad hoc network, an intranet,an extranet, a virtual private network (VPN), a local area network(LAN), a wireless LAN (WLAN), a wide area network (WAN), a wireless WAN(WWAN), a metropolitan area network (MAN), a portion of the Internet, aportion of the Public Switched Telephone Network (PSTN), a cellulartelephone network, another type of network, or a combination of two ormore such networks.

Social network system 120 a is a network-addressable computing systemthat can host one or more social graphs. Social networking system 120 acan generate, store, receive, and transmit social networking data.Social networking system 120 a can be accessed by the other componentsof system 100 either directly or via network 160. Game networking system120 b is a network-addressable computing system that can host one ormore online games. Game networking system 120 b can generate, store,receive, and transmit game-related data, such as, for example, gameaccount data, game input, game state data, and game displays. Gamenetworking system 120 b can be accessed by the other components ofsystem 100 either directly or via network 160. Player 101 may use clientsystem 130 to access, send data to, and receive data from social networksystem 120 a and game networking system 120 b. Client system 130 canaccess social networking system 120 a or game networking system 120 bdirectly, via network 160, or via a third-party system. As an exampleand not by way of limitation, client system 130 may access gamenetworking system 120 b via social networking system 120 a. Clientsystem 130 can be any suitable computing device, such as a personalcomputer, laptop, cellular phone, smart phone, computing tablet, etc.

Although FIG. 1 illustrates a particular number of players 101, socialnetworking system 120 a, game networking system 120 b, client system130, and network 160, this disclosure contemplates any suitable numberof players 101, social networking systems 120 a, game networking systems120 b, client systems 130, and networks 160. As an example and not byway of limitation, system 100 may include one or more game networkingsystems 120 b and no social networking systems 120 a. As another exampleand not by way of limitation, system 100 may include a system thatcomprises both social networking system 120 a and game networking system120 b. Moreover, although FIG. 1 illustrates a particular arrangement ofplayer 101, social networking system 120 a, game networking system 120b, client system 130, and network 160, this disclosure contemplates anysuitable arrangement of player 101, social network system 120 a, gamenetworking system 120 b, client system 130, and network 160.

The components of system 100 may be connected to each other using anysuitable connections 110. For example, suitable connections 110 includewireline (such as, for example, Digital Subscriber Line (DSL) or DataOver Cable Service Interface Specification (DOCSIS)), wireless (such as,for example, Wi-Fi or Worldwide Interoperability for Microwave Access(WiMAX)) or optical (such as, for example, Synchronous Optical Network(SONET) or Synchronous Digital Hierarchy (SDH)) connections. Inparticular embodiments, one or more connections 110 each include an adhoc network, an intranet, an extranet, a VPN, a LAN, a WLAN, a WAN, aWWAN, a MAN, a portion of the Internet, a portion of the PSTN, acellular telephone network, or another type of connection, or acombination of two or more such connections. Connections 110 need notnecessarily be the same throughout system 100. One or more firstconnections 110 may differ in one or more respects from one or moresecond connections 110. Although FIG. 1 illustrates particularconnections between player 101, social networking system 120 a, gamenetworking system 120 b, client system 130, and network 160, thisdisclosure contemplates any suitable connections between player 101,social networking system 120 a, game networking system 120 b, clientsystem 130, and network 160. As an example and not by way of limitation,in particular embodiments, client system 130 may have a directconnection to social networking system 120 a or game networking system120 b, bypassing network 160.

In an online computer game, a game engine manages the game state of thegame. Game state comprises all game play parameters, including playercharacter state, non-player character (NPC) state, in-game object state,game world state (e.g., internal game clocks, game environment), andother game play parameters. Each player 101 controls one or more playercharacters (PCs). The game engine controls all other aspects of thegame, including non-player characters (NPCs), and in-game objects. Thegame engine also manages game state, including player character statefor currently active (online) and inactive (offline) players.

An online game can be hosted by game networking system 120 b, which canbe accessed using any suitable connection with a suitable client system130. A player may have a game account on game networking system 120 b,wherein the game account can contain a variety of information associatedwith the player (e.g., the player's personal information, financialinformation, purchase history, player character state, game state). Insome embodiments, a player may play multiple games on game networkingsystem 120 b, which may maintain a single game account for the playerwith respect to all the games, or multiple individual game accounts foreach game with respect to the player. In some embodiments, gamenetworking system 120 b can assign a unique identifier to each player101 of an online game hosted on game networking system 120 b. Gamenetworking system 120 b can determine that a player 101 is accessing theonline game by reading the user's cookies, which may be appended to HTTPrequests transmitted by client system 130, and/or by the player 101logging onto the online game.

In particular embodiments, player 101 may access an online game andcontrol the game's progress via client system 130 (e.g., by inputtingcommands to the game at the client device). Client system 130 candisplay the game interface, receive inputs from player 101, transmittinguser inputs or other events to the game engine, and receive instructionsfrom the game engine. The game engine can be executed on any suitablesystem (such as, for example, client system 130, social networkingsystem 120 a, or game networking system 120 b). As an example and not byway of limitation, client system 130 can download client components ofan online game, which are executed locally, while a remote game server,such as game networking system 120 b, provides backend support for theclient components and may be responsible for maintaining applicationdata of the game, processing the inputs from the player, updating and/orsynchronizing the game state based on the game logic and each input fromthe player, and transmitting instructions to client system 130. Asanother example and not by way of limitation, each time player 101provides an input to the game through the client system 130 (such as,for example, by typing on the keyboard or clicking the mouse of clientsystem 130), the client components of the game may transmit the player'sinput to game networking system 120 b.

Game Systems, Social Networks, and Social Graphs

In an online multiplayer game, players may control player characters(PCs), a game engine controls non-player characters (NPCs) and gamefeatures, and the game engine also manages player character state andgame state and tracks the state for currently active (i.e., online)players and currently inactive (i.e., offline) players. A playercharacter can have a set of attributes and a set of friends associatedwith the player character. As used herein, the term “player characterstate” can refer to any in-game characteristic of a player character,such as location, assets, levels, condition, health, status, inventory,skill set, name, orientation, affiliation, specialty, and so on. Playercharacters may be displayed as graphical avatars within a user interfaceof the game. In other implementations, no avatar or other graphicalrepresentation of the player character is displayed. Game stateencompasses the notion of player character state and refers to anyparameter value that characterizes the state of an in-game element, suchas a non-player character, a virtual object (such as a wall or castle),etc. The game engine may use player character state to determine theoutcome of game events, sometimes also considering set or randomvariables. Generally, a player character's probability of having a morefavorable outcome is greater when the player character has a betterstate. For example, a healthier player character is less likely to diein a particular encounter relative to a weaker player character ornon-player character. In some embodiments, the game engine can assign aunique client identifier to each player.

In particular embodiments, player 101 may access particular gameinstances of an online game. A game instance is copy of a specific gameplay area that is created during runtime. In particular embodiments, agame instance is a discrete game play area where one or more players 101can interact in synchronous or asynchronous play. A game instance maybe, for example, a level, zone, area, region, location, virtual space,or other suitable play area. A game instance may be populated by one ormore in-game objects. Each object may be defined within the gameinstance by one or more variables, such as, for example, position,height, width, depth, direction, time, duration, speed, color, and othersuitable variables. A game instance may be exclusive (i.e., accessibleby specific players) or non-exclusive (i.e., accessible by any player).In particular embodiments, a game instance is populated by one or moreplayer characters controlled by one or more players 101 and one or morein-game objects controlled by the game engine. When accessing an onlinegame, the game engine may allow player 101 to select a particular gameinstance to play from a plurality of game instances. Alternatively, thegame engine may automatically select the game instance that player 101will access. In particular embodiments, an online game comprises onlyone game instance that all players 101 of the online game can access.

In particular embodiments, a specific game instance may be associatedwith one or more specific players. A game instance is associated with aspecific player when one or more game parameters of the game instanceare associated with the specific player. As an example and not by way oflimitation, a game instance associated with a first player may be named“First Player's Play Area.” This game instance may be populated with thefirst player's PC and one or more in-game objects associated with thefirst player. In particular embodiments, a game instance associated witha specific player may only be accessible by that specific player. As anexample and not by way of limitation, a first player may access a firstgame instance when playing an online game, and this first game instancemay be inaccessible to all other players. In other embodiments, a gameinstance associated with a specific player may be accessible by one ormore other players, either synchronously or asynchronously with thespecific player's game play. As an example and not by way of limitation,a first player may be associated with a first game instance, but thefirst game instance may be accessed by all first-degree friends in thefirst player's social network. In particular embodiments, the gameengine may create a specific game instance for a specific player whenthat player accesses the game. As an example and not by way oflimitation, the game engine may create a first game instance when afirst player initially accesses an online game, and that same gameinstance may be loaded each time the first player accesses the game. Asanother example and not by way of limitation, the game engine may createa new game instance each time a first player accesses an online game,wherein each game instance may be created randomly or selected from aset of predetermined game instances. In particular embodiments, the setof in-game actions available to a specific player may be different in agame instance that is associated with that player compared to a gameinstance that is not associated with that player. The set of in-gameactions available to a specific player in a game instance associatedwith that player may be a subset, superset, or independent of the set ofin-game actions available to that player in a game instance that is notassociated with him. As an example and not by way of limitation, a firstplayer may be associated with Blackacre Farm in an online farming game.The first player may be able to plant crops on Blackacre Farm. If thefirst player accesses game instance associated with another player, suchas Whiteacre Farm, the game engine may not allow the first player toplant crops in that game instance. However, other in-game actions may beavailable to the first player, such as watering or fertilizing crops onWhiteacre Farm.

In particular embodiments, a game engine can interface with a socialgraph. Social graphs are models of connections between entities (e.g.,individuals, users, contacts, friends, players, player characters,non-player characters, businesses, groups, associations, concepts,etc.). These entities are considered “users” of the social graph; assuch, the terms “entity” and “user” may be used interchangeably whenreferring to social graphs herein. A social graph can have a node foreach entity and edges to represent relationships between entities. Anode in a social graph can represent any entity. In particularembodiments, a unique client identifier can be assigned to each user inthe social graph. This disclosure assumes that at least one entity of asocial graph is a player or player character in an online multiplayergame, though this disclosure any suitable social graph users.

The minimum number of edges required to connect a player (or playercharacter) to another user is considered the degree of separationbetween them. For example, where the player and the user are directlyconnected (one edge), they are deemed to be separated by one degree ofseparation. The user would be a so-called “first-degree friend” of theplayer. Where the player and the user are connected through one otheruser (two edges), they are deemed to be separated by two degrees ofseparation. This user would be a so-called “second-degree friend” of theplayer. Where the player and the user are connected through N edges (orN−1 other users), they are deemed to be separated by N degrees ofseparation. This user would be a so-called “Nth-degree friend.” As usedherein, the term “friend” means only first-degree friends, unlesscontext suggests otherwise.

Within the social graph, each player (or player character) has a socialnetwork. A player's social network includes all users in the socialgraph within Nmax degrees of the player, where Nmax is the maximumdegree of separation allowed by the system managing the social graph(such as, for example, social networking system 120 a or game networkingsystem 120 b). In one embodiment, Nmax equals 1, such that the player'ssocial network includes only first-degree friends. In anotherembodiment, Nmax is unlimited and the player's social network iscoextensive with the social graph.

In particular embodiments, the social graph is managed by gamenetworking system 120 b, which is managed by the game operator. In otherembodiments, the social graph is part of a social networking system 120a managed by a third-party (e.g., Facebook, Friendster, Myspace). In yetother embodiments, player 101 has a social network on both gamenetworking system 120 b and social networking system 120 a, whereinplayer 101 can have a social network on the game networking system 120 bthat is a subset, superset, or independent of the player's socialnetwork on social networking system 120 a. In such combined systems,game network system 120 b can maintain social graph information withedge type attributes that indicate whether a given friend is an “in-gamefriend,” an “out-of-game friend,” or both. The various embodimentsdisclosed herein are operable when the social graph is managed by socialnetworking system 120 a, game networking system 120 b, or both.

FIG. 2 shows an example of a social network within a social graph. Asshown, Player 201 can be associated, connected or linked to variousother users, or “friends,” within the social network 250. Theseassociations, connections or links can track relationships between userswithin the social network 250 and are commonly referred to as online“friends” or “friendships” between users. Each friend or friendship in aparticular user's social network within a social graph is commonlyreferred to as a “node.” For purposes of illustration and not by way oflimitation, the details of social network 250 will be described inrelation to Player 201. As used herein, the terms “player” and “user”can be used interchangeably and can refer to any user or character in anonline multiuser game system or social networking system. As usedherein, the term “friend” can mean any node within a player's socialnetwork.

As shown in FIG. 2, Player 201 has direct connections with severalfriends. When Player 201 has a direct connection with another individualthat connection is referred to as a first-degree friend. In socialnetwork 250, Player 201 has two first-degree friends. That is, Player201 is directly connected to Friend 1 ₁ 211 and Friend 2 ₁ 221. In asocial graph, it is possible for individuals to be connected to otherindividuals through their first-degree friends (i.e., friends offriends). As described above, each edge required to connect a player toanother user is considered the degree of separation. For example, FIG. 2shows that Player 201 has three second-degree friends to which he isconnected via his connection to his first-degree friends. Second-degreeFriend 1 ₂ 212 and Friend 2 ₂ 222 are connected to Player 201 via hisfirst-degree Friend 1 ₁ 211. The limit on the depth of friendconnections, or the number of degrees of separation for associations,that Player 201 is allowed is typically dictated by the restrictions andpolicies implemented by social networking system 120 a.

In various embodiments, Player 201 can have Nth-degree friends connectedto him through a chain of intermediary degree friends as indicated inFIG. 2. For example, Nth-degree Friend 1 _(N) 219 is connected to Player201 via second-degree Friend 3 ₂ 232 and one or more other higher-degreefriends. Various embodiments may take advantage of and utilize thedistinction between the various degrees of friendship relative to Player201.

In particular embodiments, a player (or player character) can have asocial graph within an online multiplayer game that is maintained by thegame engine and another social graph maintained by a separate socialnetworking system. FIG. 2 depicts an example of in-game social network260 and out-of-game social network 250. In this example, Player 201 hasout-of-game connections 255 to a plurality of friends, formingout-of-game social network 250. Here, Friend 1 ₁ 211 and Friend 2 ₁ 221are first-degree friends with Player 201 in his out-of-game socialnetwork 250. Player 201 also has in-game connections 265 to a pluralityof players, forming in-game social network 260. Here, Friend 2 ₁ 221,Friend 3 ₁ 231, and Friend 4 ₁ 241 are first-degree friends with Player201 in his in-game social network 260. In some embodiments, it ispossible for a friend to be in both the out-of-game social network 250and the in-game social network 260. Here, Friend 2 ₁ 221 has both anout-of-game connection 255 and an in-game connection 265 with Player201, such that Friend 2 ₁ 221 is in both Player 201's in-game socialnetwork 260 and Player 201's out-of-game social network 250.

As with other social networks, Player 201 can have second-degree andhigher-degree friends in both his in-game and out of game socialnetworks. In some embodiments, it is possible for Player 201 to have afriend connected to him both in his in-game and out-of-game socialnetworks, wherein the friend is at different degrees of separation ineach network. For example, if Friend 2 ₂ 222 had a direct in-gameconnection with Player 201, Friend 2 ₂ 222 would be a second-degreefriend in Player 201's out-of-game social network, but a first-degreefriend in Player 201's in-game social network. In particularembodiments, a game engine can access in-game social network 260,out-of-game social network 250, or both.

In particular embodiments, the connections in a player's in-game socialnetwork can be formed both explicitly (e.g., users must “friend” eachother) and implicitly (e.g., system observes user behaviors and“friends” users to each other). Unless otherwise indicated, reference toa friend connection between two or more players can be interpreted tocover both explicit and implicit connections, using one or more socialgraphs and other factors to infer friend connections. The friendconnections can be unidirectional or bidirectional. It is also not alimitation of this description that two players who are deemed “friends”for the purposes of this disclosure are not friends in real life (i.e.,in disintermediated interactions or the like), but that could be thecase.

A game event may be an outcome of an engagement, a provision of access,rights and/or benefits, or the obtaining of some assets (e.g., health,money, strength, inventory, land, etc.). A game engine determines theoutcome of a game event according to a variety of factors, such as thegame rules, a player character's in-game actions, player characterstate, game state, interactions of other player characters, and randomcalculations. Engagements can include simple tasks (e.g., plant a crop,clean a stove), complex tasks (e.g., build a farm or business, run acafé), or other events.

An online game can be hosted by a game networking system, which can beaccessed over any suitable network with an appropriate client system. Aplayer may have a game system account on game system, wherein the gamesystem account can contain a variety of information about the player(e.g., the player's personal information, player character state, gamestate, etc.). In various embodiments, an online game can be embeddedinto a third-party website. The game can be hosted by the networkingsystem of the third-party website, or it can be hosted on game systemand merely accessed via the third-party website. The embedded onlinegame can be hosted solely on a server of game system or using athird-party vendor server. In addition, any combination of the functionsof the present disclosure can be hosted on or provided from any numberof distributed network resources. For example, one or more executablecode objects that implement all or a portion of the game can bedownloaded to a client system for execution.

FIG. 3 illustrates a flow diagram of an example of a method fordetecting and scoring churn in an online social game. At operation 302,online engagements of a group of players of an online game are monitoredduring a churn prediction model training period. The churn predictionmodel training period includes the last first number of days (e.g., last90 days). For example, a player's engagement may include the number ofdays the player has played or accessed the online game for each week fora period of 90 days. It should be noted that players from the group ofplayers have already installed the online game during the churn modeltraining period. As such, the maximum online engagement of a player maybe seven days a week for the last 90 days. The minimum online engagementof a player may be zero days a week for the last 90 days. Also, theonline engagement may vary week by week.

At operation 304, online engagement scores for the group of players arecomputed based on a number of days the group of players has played onthe online game within a periodic number of days (e.g., a week) withinthe churn model training period (e.g. last 90 days). A score is assignedbased on the online engagement. For example, a score of 1 may beassigned when the player has played the online game one day out of weekor a score of 4 may be assigned when the player has played the onlinegame one day a week for four weeks.

At operation 306, exponential weights are assigned to the onlineengagement scores so that a weight of an online engagement score ishigher when occurred more recently. The exponential weights are used tocompute a weighted exponential moving average of the online engagementscores of the group of players of the online game during the churn modeltraining period (e.g., last 90 days). The weight is chosen so that aplayer's engagement score is ranked higher when it occurs more recentlyas opposed to a player who has strong early engagement but recentlytapered off. FIG. 9 illustrates an example of a table 900 illustratingthe weighting scheme with their corresponding online engagement scores.Column 902 represents scores of players in the group from 4 weeks prior.Column 904 represents scores of players in the group from 3 weeks prior.Column 906 represents scores of players in the group from 2 weeks prior.Column 908 represents scores of the players the directly preceding week.Column 910 represents the weighted scores of players in the group.

At operation 308, the weighted exponential moving average of the onlineengagement scores of the group of players of the online game is used todetermine an online engagement threshold value of a churn predictionmodel for the online game. The churn prediction model is generated bytraining a simple naïve Bayesian classifier that computes the posteriorprobabilities of a player to be a likely churner based on the learneddistributions as well as the priors. For example, the priorprobabilities turn out to be 60% for a user to stay in the game and 40%for a user to churn. In that example, the churn model derives athreshold value of 2.4 for the engagement score, meaning that the churnmodel predicts a player to be a churner if the engagement score is belowthat threshold value of 2.4.

In one embodiment, the churn score computation algorithm may be asfollows:Churn-score=C.w1*0.4+(0.6)*((C.w2*0.4)+(0.6)*(C.w3*0.4+(0.6)*(C.w4*0.4)))where w1=s number of days played in previous week, w2=s number of daysplayed 2 weeks ago, w3=s number of days played 3 weeks ago, w4=s numberof days played 4 weeks ago

At operation 310, the online engagement threshold value is applied to aweighted exponential moving average of an online engagement score of aplayer during an observation period comprising the last second number ofdays (e.g., last 30 days) to determine a churn probability of the playerwithin a prediction period comprising the next third number of days(e.g., the next 30 days). For example, a player having a weightedexponential moving average online engagement score of 2.1 is likely tochurn because the score is less than the threshold value of 2.4.

In one embodiment, a probability of whether the player is likely tochurn within the next 30 days may be derived by comparing the score ofthe player and the threshold value.

To illustrate the different time period, FIG. 8 is a block diagramillustrating an example of a timeline for churn prediction. The modeltraining period 812 is before the present date, today 810. The modeltraining period 812 may include for example 90 days. The time period 802represents a one month period 60 to 90 days before today 810. The timeperiod 804 represents a one month period 30 to 60 days before today 810.The observation period 806 represents a one month period 0 to 30 daysbefore today 810. The observation period 806 is associated with theplayer. The model training period 812 is associated with the group ofplayers. The prediction period 808 represents the next 30 days aftertoday 810.

FIG. 4 illustrates a flow diagram of an example of a method forincreasing retention using churn prediction.

At operation 402, a churn probability of a player with the churn ratemodel applied to an online engagement history of the player isdetermined using the process as previously described with respect toFIG. 3.

At operation 404, a message is generated to the player to keep theplayer engaged in the online game when the churn probability of theplayer exceeds a predetermined churn probability threshold.

At operation 406, a message is generated to the player to request theplayer to complete a task in the online game when the churn probabilityof the player exceeds a predetermined churn probability threshold. Forexample, the player is invited to complete a new easier task or is givenclues to complete an existing task.

At operation 408, another player connected to the player via a socialnetwork is identified to help the player complete a task in the onlinegame when the churn probability of the player exceeds a predeterminedchurn probability threshold.

At operation 410, a message is generated to the player to request helpfrom the other player to complete the task in the online game of theplayer.

Data Flow

FIG. 5A illustrates an example data flow between the components ofsystem 500. In particular embodiments, system 500 can include clientsystem 530, social networking system 520 a, and game networking system520 b. The components of system 500 can be connected to each other inany suitable configuration, using any suitable type of connection. Thecomponents may be connected directly or over any suitable network.Client system 530, social networking system 520 a, and game networkingsystem 520 b can each have one or more corresponding data stores such aslocal data store 535, social data store 545, and game data store 565,respectively. Social networking system 520 a and game networking system520 b can also have one or more servers that can communicate with clientsystem 530 over an appropriate network. Social networking system 520 aand game networking system 520 b can have, for example, one or moreinternet servers for communicating with client system 530 via theInternet. Similarly, social networking system 520 a and game networkingsystem 520 b can have one or more mobile servers for communicating withclient system 530 via a mobile network (e.g., GSM, PCS, Wi-Fi, WPAN,etc.). In some embodiments, one server may be able to communicate withclient system 530 over both the Internet and a mobile network. In otherembodiments, separate servers can be used.

Client system 530 can receive and transmit data 523 to and from gamenetworking system 520 b. This data can include, for example, webpages,messages, game inputs, game displays, HTTP packets, data requests,transaction information, updates, and other suitable data. At some othertime, or at the same time, game networking system 520 b can communicatedata 543, 547 (e.g., game state information, game system accountinformation, page info, messages, data requests, updates, etc.) withother networking systems, such as social networking system 520 a (e.g.,Facebook, Myspace, etc.). Client system 530 can also receive andtransmit data 527 to and from social networking system 520 a. This datacan include, for example, webpages, messages, social graph information,social network displays, HTTP packets, data requests, transactioninformation, updates, and other suitable data.

Communication between client system 530, social networking system 520 a,and game networking system 520 b can occur over any appropriateelectronic communication medium or network using any suitablecommunications protocols. For example, client system 530, as well asvarious servers of the systems described herein, may include TransportControl Protocol/Internet Protocol (TCP/IP) networking stacks to providefor datagram and transport functions. Of course, any other suitablenetwork and transport layer protocols can be utilized.

In addition, hosts or end-systems described herein may use a variety ofhigher layer communications protocols, including client-server (orrequest-response) protocols, such as the HyperText Transfer Protocol(HTTP) and other communications protocols, such as HTTP-S, FTP, SNMP,TELNET, and a number of other protocols, may be used. In addition, aserver in one interaction context may be a client in another interactioncontext. In particular embodiments, the information transmitted betweenhosts may be formatted as HyperText Markup Language (HTML) documents.Other structured document languages or formats can be used, such as XML,and the like. Executable code objects, such as JavaScript andActionScript, can also be embedded in the structured documents.

In some client-server protocols, such as the use of HTML over HTTP, aserver generally transmits a response to a request from a client. Theresponse may comprise one or more data objects. For example, theresponse may comprise a first data object, followed by subsequentlytransmitted data objects. In particular embodiments, a client requestmay cause a server to respond with a first data object, such as an HTMLpage, which itself refers to other data objects. A client application,such as a browser, will request these additional data objects as itparses or otherwise processes the first data object.

In particular embodiments, an instance of an online game can be storedas a set of game state parameters that characterize the state of variousin-game objects, such as, for example, player character stateparameters, non-player character parameters, and virtual itemparameters. In particular embodiments, game state is maintained in adatabase as a serialized, unstructured string of text data as aso-called Binary Large Object (BLOB). When a player accesses an onlinegame on game networking system 520 b, the BLOB containing the game statefor the instance corresponding to the player can be transmitted toclient system 530 for use by a client-side executed object to process.In particular embodiments, the client-side executable may be aFLASH-based game, which can de-serialize the game state data in theBLOB. As a player plays the game, the game logic implemented at clientsystem 530 maintains and modifies the various game state parameterslocally. The client-side game logic may also batch game events, such asmouse clicks, and transmit these events to game networking system 520 b.Game networking system 520 b may itself operate by retrieving a copy ofthe BLOB from a database or an intermediate memory cache (memcache)layer. Game networking system 520 b can also de-serialize the BLOB toresolve the game state parameters and execute its own game logic basedon the events in the batch file of events transmitted by the client tosynchronize the game state on the server side. Game networking system520 b may then re-serialize the game state, now modified, into a BLOBand pass this to a memory cache layer for lazy updates to a persistentdatabase.

With a client-server environment in which the online games may run, oneserver system, such as game networking system 520 b, may supportmultiple client systems 530. At any given time, there may be multipleplayers at multiple client systems 530 all playing the same online game.In practice, the number of players playing the same game at the sametime may be very large. As the game progresses with each player,multiple players may provide different inputs to the online game attheir respective client systems 530, and multiple client systems 530 maytransmit multiple player inputs and/or game events to game networkingsystem 520 b for further processing. In addition, multiple clientsystems 530 may transmit other types of application data to gamenetworking system 520 b.

In particular embodiments, a computed-implemented game may be atext-based or turn-based game implemented as a series of web pages thatare generated after a player selects one or more actions to perform. Theweb pages may be displayed in a browser client executed on client system530. As an example and not by way of limitation, a client applicationdownloaded to client system 530 may operate to serve a set of webpagesto a player. As another example and not by way of limitation, acomputer-implemented game may be an animated or rendered game executableas a stand-alone application or within the context of a webpage or otherstructured document. In particular embodiments, the computer-implementedgame may be implemented using Adobe Flash-based technologies. As anexample and not by way of limitation, a game may be fully or partiallyimplemented as a SWF object that is embedded in a web page andexecutable by a Flash media player plug-in. In particular embodiments,one or more described webpages may be associated with or accessed bysocial networking system 520 a. This disclosure contemplates using anysuitable application for the retrieval and rendering of structureddocuments hosted by any suitable network-addressable resource orwebsite.

Application event data of a game is any data relevant to the game (e.g.,player inputs). In particular embodiments, each application datum mayhave a name and a value, and the value of the application datum maychange (i.e., be updated) at any time. When an update to an applicationdatum occurs at client system 530, either caused by an action of a gameplayer or by the game logic itself, client system 530 may need to informgame networking system 520 b of the update. For example, if the game isa farming game with a harvest mechanic (such as Zynga FarmVille), anevent can correspond to a player clicking on a parcel of land to harvesta crop. In such an instance, the application event data may identify anevent or action (e.g., harvest) and an object in the game to which theevent or action applies. For illustration purposes and not by way oflimitation, system 500 is discussed in reference to updating amulti-player online game hosted on a network-addressable system (suchas, for example, social networking system 520 a or game networkingsystem 520 b), where an instance of the online game is executed remotelyon a client system 530, which then transmits application event data tothe hosting system such that the remote game server synchronizes gamestate associated with the instance executed by the client system 530.

In particular embodiment, one or more objects of a game may berepresented as an Adobe Flash object. Flash may manipulate vector andraster graphics, and supports bidirectional streaming of audio andvideo. “Flash” may mean the authoring environment, the player, or theapplication files. In particular embodiments, client system 530 mayinclude a Flash client. The Flash client may be configured to receiveand run Flash application or game object code from any suitablenetworking system (such as, for example, social networking system 520 aor game networking system 520 b). In particular embodiments, the Flashclient may be run in a browser client executed on client system 530. Aplayer can interact with Flash objects using client system 530 and theFlash client. The Flash objects can represent a variety of in-gameobjects. Thus, the player may perform various in-game actions on variousin-game objects by make various changes and updates to the associatedFlash objects. In particular embodiments, in-game actions can beinitiated by clicking or similarly interacting with a Flash object thatrepresents a particular in-game object. For example, a player caninteract with a Flash object to use, move, rotate, delete, attack,shoot, or harvest an in-game object. This disclosure contemplatesperforming any suitable in-game action by interacting with any suitableFlash object. In particular embodiments, when the player makes a changeto a Flash object representing an in-game object, the client-executedgame logic may update one or more game state parameters associated withthe in-game object. To ensure synchronization between the Flash objectshown to the player at client system 530, the Flash client may send theevents that caused the game state changes to the in-game object to gamenetworking system 520 b. However, to expedite the processing and hencethe speed of the overall gaming experience, the Flash client may collecta batch of some number of events or updates into a batch file. Thenumber of events or updates may be determined by the Flash clientdynamically or determined by game networking system 520 b based onserver loads or other factors. For example, client system 530 may send abatch file to game networking system 520 b whenever 50 updates have beencollected or after a threshold period of time, such as every minute.

As used herein, the term “application event data” may refer to any datarelevant to a computer-implemented game application that may affect oneor more game state parameters, including, for example and withoutlimitation, changes to player data or metadata, changes to player socialconnections or contacts, player inputs to the game, and events generatedby the game logic. In particular embodiments, each application datum mayhave a name and a value. The value of an application datum may change atany time in response to the game play of a player or in response to thegame engine (e.g., based on the game logic). In particular embodiments,an application data update occurs when the value of a specificapplication datum is changed. In particular embodiments, eachapplication event datum may include an action or event name and a value(such as an object identifier). Thus, each application datum may berepresented as a name-value pair in the batch file. The batch file mayinclude a collection of name-value pairs representing the applicationdata that have been updated at client system 530. In particularembodiments, the batch file may be a text file and the name-value pairsmay be in string format.

In particular embodiments, when a player plays an online game on clientsystem 530, game networking system 520 b may serialize all thegame-related data, including, for example and without limitation, gamestates, game events, user inputs, for this particular user and thisparticular game into a BLOB and stores the BLOB in a database. The BLOBmay be associated with an identifier that indicates that the BLOBcontains the serialized game-related data for a particular player and aparticular online game. In particular embodiments, while a player is notplaying the online game, the corresponding BLOB may be stored in thedatabase. This enables a player to stop playing the game at any timewithout losing the current state of the game the player is in. When aplayer resumes playing the game next time, game networking system 520 bmay retrieve the corresponding BLOB from the database to determine themost-recent values of the game-related data. In particular embodiments,while a player is playing the online game, game networking system 520 bmay also load the corresponding BLOB into a memory cache so that thegame system may have faster access to the BLOB and the game-related datacontained therein.

Social Networking System 520 a and Game Networking System 520 bcommunicate with a Churn Prediction Server 501. An API may be providedto interface both Social Networking System 520 a and Game networkingsystem 520 b with the Churn Prediction Server 501. The Churn PredictionServer 501 may be configured to analyze data including for example, afrequency of users online engagements in the Social Networking System520 a and/or the Game Networking System 520 b. Based on the analysis ofthe data, the Churn Prediction Server 501 is able to predict whether auser is likely to churn in the Game Networking System 520 b and/or theSocial Networking System 520 a. Furthermore, the Churn Prediction Server501 can also be configured to provide recommendations to the GameNetworking System 520 b on how to improve retaining the user/player tocontinue playing on the Game Networking System 520 b.

FIG. 5B is an example of the Churn Prediction server 501. The ChurnPrediction Server 501 may include an analysis module 502, arecommendation module 504, and a storage device 516. The analysis module502 is configured to analyze data related to playerengagements/interactions on the Game Networking System 520 b and/or theSocial Networking System 520 a. The analysis module 502 includes anonline engagement monitoring module 506, an online engagement scoremodule 508, a moving average computation module 510, a churn predictionmodule 512, and a churn probability module 514.

The recommendation module 504 is configured to provide a recommendationto the Game Networking System 520 b on strategies for improvingretaining a player on the Game Networking System 520 b and increasingthe player's online engagements and interactions on the Game NetworkingSystem 520 b.

The storage device 516 may store data related to the modules 506, 508,510, 512, 514, and the recommendation module 504 for further analysis.The storage device 516 may store historical trends and baseline valuesof users based on the data related to user communications andinteractions on the Game Networking System 520 b and/or the SocialNetworking System 520 a.

The online engagement monitoring module 506 monitors online engagementsof a group of players of an online game during a churn prediction modeltraining period, the training period comprising the last first number ofdays.

The online engagement score module 508 computes online engagement scoresfor the group of players based on a number of days the group of playershas played on the online game within a periodic number of days withinthe churn model training period.

The moving average computation module 510 assigns exponential weights tothe online engagement scores so that a weight of an online engagementscore is higher when occurred more recently. The moving averagecomputation module 510 then uses the exponential weights to compute aweighted exponential moving average of the online engagement scores ofthe group of players of the online game during the churn model trainingperiod.

The churn prediction module 512 uses the weighted exponential movingaverage of the online engagement scores of the group of players of theonline game to determine an online engagement threshold value of a churnprediction model for the online game.

The churn probability module 514 applies the online engagement thresholdvalue to a weighted exponential moving average of an online engagementscore of a player during an observation period comprising the lastsecond number of days to determine a churn probability of the playerwithin a prediction period comprising the next third number of days.

The storage device 516 stores the weighted exponential moving average ofthe online engagement scores of the group of players of the online gameduring the churn model training period, the online engagement thresholdvalue of a churn prediction model for the online game for the churnmodel training period, and the churn probability of the player withinthe prediction period.

System and Methods

In particular embodiments, one or more described webpages may beassociated with a networking system or networking service. However,alternate embodiments may have application to the retrieval andrendering of structured documents hosted by any type of networkaddressable resource or web site. Additionally, as used herein, a usermay be an individual, a group, or an entity (such as a business or thirdparty application).

Particular embodiments may operate in a wide area network environment,such as the Internet, including multiple network addressable systems.FIG. 6 illustrates an example network environment, in which variousexample embodiments may operate. Network cloud 660 generally representsone or more interconnected networks, over which the systems and hostsdescribed herein can communicate. Network cloud 660 may includepacket-based wide area networks (such as the Internet), privatenetworks, wireless networks, satellite networks, cellular networks,paging networks, and the like. As FIG. 6 illustrates, particularembodiments may operate in a network environment comprising one or morenetworking systems, such as social networking system 620 a, gamenetworking system 620 b, and one or more client systems 630. Thecomponents of social networking system 620 a and game networking system620 b operate analogously; as such, hereinafter they may be referred tosimply at networking system 620. Client systems 630 are operablyconnected to the network environment via a network service provider, awireless carrier, or any other suitable means.

Networking system 620 is a network addressable system that, in variousexample embodiments, comprises one or more physical servers 622 and datastores 624. The one or more physical servers 622 are operably connectedto computer network 660 via, by way of example, a set of routers and/ornetworking switches 626. In an example embodiment, the functionalityhosted by the one or more physical servers 122 may include web or HTTPservers, FTP servers, as well as, without limitation, webpages andapplications implemented using Common Gateway Interface (CGI) script,PHP Hyper-text Preprocessor (PHP), Active Server Pages (ASP), Hyper TextMarkup Language (HTML), Extensible Markup Language (XML), Java,JavaScript, Asynchronous JavaScript and XML (AJAX), Flash, ActionScript,and the like.

Physical servers 622 may host functionality directed to the operationsof networking system 620. Hereinafter servers 622 may be referred to asserver 622, although server 622 may include numerous servers hosting,for example, networking system 620, as well as other contentdistribution servers, data stores, and databases. Data store 624 maystore content and data relating to, and enabling, operation ofnetworking system 620 as digital data objects. A data object, inparticular embodiments, is an item of digital information typicallystored or embodied in a data file, database, or record. Content objectsmay take many forms, including: text (e.g., ASCII, SGML, HTML), images(e.g., jpeg, tif and gif), graphics (vector-based or bitmap), audio,video (e.g., mpeg), or other multimedia, and combinations thereof.Content object data may also include executable code objects (e.g.,games executable within a browser window or frame), podcasts, etc.Logically, data store 624 corresponds to one or more of a variety ofseparate and integrated databases, such as relational databases andobject-oriented databases, that maintain information as an integratedcollection of logically related records or files stored on one or morephysical systems. Structurally, data store 624 may generally include oneor more of a large class of data storage and management systems. Inparticular embodiments, data store 624 may be implemented by anysuitable physical system(s) including components, such as one or moredatabase servers, mass storage media, media library systems, storagearea networks, data storage clouds, and the like. In one exampleembodiment, data store 624 includes one or more servers, databases(e.g., MySQL), and/or data warehouses. Data store 624 may include dataassociated with different networking system 620 users and/or clientsystems 630.

Client system 630 is generally a computer or computing device includingfunctionality for communicating (e.g., remotely) over a computernetwork. Client system 630 may be a desktop computer, laptop computer,personal digital assistant (PDA), in- or out-of-car navigation system,smart phone or other cellular or mobile phone, or mobile gaming device,among other suitable computing devices. Client system 630 may executeone or more client applications, such as a web browser (e.g., MicrosoftInternet Explorer, Mozilla Firefox, Apple Safari, Google Chrome, andOpera), to access and view content over a computer network. Inparticular embodiments, the client applications allow a user of clientsystem 630 to enter addresses of specific network resources to beretrieved, such as resources hosted by networking system 620. Theseaddresses can be Uniform Resource Locators (URLs) and the like. Inaddition, once a page or other resource has been retrieved, the clientapplications may provide access to other pages or records when the user“clicks” on hyperlinks to other resources. By way of example, suchhyperlinks may be located within the webpages and provide an automatedway for the user to enter the URL of another page and to retrieve thatpage.

A webpage or resource embedded within a webpage, which may itselfinclude multiple embedded resources, may include data records, such asplain textual information, or more complex digitally encoded multimediacontent, such as software programs or other code objects, graphics,images, audio signals, videos, and so forth. One prevalent markuplanguage for creating webpages is the Hypertext Markup Language (HTML).Other common web browser-supported languages and technologies includethe Extensible Markup Language (XML), the Extensible Hypertext MarkupLanguage (XHTML), JavaScript, Flash, ActionScript, Cascading Style Sheet(CSS), and, frequently, Java. By way of example, HTML enables a pagedeveloper to create a structured document by denoting structuralsemantics for text and links, as well as images, web applications, andother objects that can be embedded within the page. Generally, a webpagemay be delivered to a client as a static document; however, through theuse of web elements embedded in the page, an interactive experience maybe achieved with the page or a sequence of pages. During a user sessionat the client, the web browser interprets and displays the pages andassociated resources received or retrieved from the website hosting thepage, as well as, potentially, resources from other websites.

When a user at a client system 630 desires to view a particular webpage(hereinafter also referred to as target structured document) hosted bynetworking system 620, the user's web browser, or other documentrendering engine or suitable client application, formulates andtransmits a request to networking system 620. The request generallyincludes a URL or other document identifier as well as metadata or otherinformation. By way of example, the request may include informationidentifying the user, such as a user ID, as well as informationidentifying or characterizing the web browser or operating systemrunning on the user's client computing device 630. The request may alsoinclude location information identifying a geographic location of theuser's client system or a logical network location of the user's clientsystem. The request may also include a timestamp identifying when therequest was transmitted.

Although the example network environment described above and illustratedin FIG. 6 described with respect to social networking system 620 a andgame networking system 620 b, this disclosure encompasses any suitablenetwork environment using any suitable systems. As an example and not byway of limitation, the network environment may include online mediasystems, online reviewing systems, online search engines, onlineadvertising systems, or any combination of two or more such systems.

FIG. 7 illustrates an example computing system architecture, which maybe used to implement a server 622 or a client system 630. In oneembodiment, hardware system 700 comprises a processor 702, a cachememory 704, and one or more executable modules and drivers, stored on atangible computer readable medium, directed to the functions describedherein. Additionally, hardware system 700 may include a high performanceinput/output (I/O) bus 706 and a standard I/O bus 708. A host bridge 710may couple processor 702 to high performance I/O bus 706, whereas I/Obus bridge 712 couples the two buses 706 and 708 to each other. A systemmemory 714 and one or more network/communication interfaces 716 maycouple to bus 706. Hardware system 700 may further include video memory(not shown) and a display device coupled to the video memory. Massstorage 718 and I/O ports 720 may couple to bus 708. Hardware system 700may optionally include a keyboard, a pointing device, and a displaydevice (not shown) coupled to bus 708. Collectively, these elements areintended to represent a broad category of computer hardware systems,including but not limited to general purpose computer systems based onthe x86-compatible processors manufactured by Intel Corporation of SantaClara, Calif., and the x86-compatible processors manufactured byAdvanced Micro Devices (AMD), Inc., of Sunnyvale, Calif., as well as anyother suitable processor.

The elements of hardware system 700 are described in greater detailbelow. In particular, network interface 716 provides communicationbetween hardware system 700 and any of a wide range of networks, such asan Ethernet (e.g., IEEE 802.3) network, a backplane, etc. Mass storage718 provides permanent storage for the data and programming instructionsto perform the above-described functions implemented in servers 422,whereas system memory 714 (e.g., DRAM) provides temporary storage forthe data and programming instructions when executed by processor 702.I/O ports 720 are one or more serial and/or parallel communication portsthat provide communication between additional peripheral devices, whichmay be coupled to hardware system 700.

Hardware system 700 may include a variety of system architectures andvarious components of hardware system 700 may be rearranged. Forexample, cache 704 may be on-chip with processor 702. Alternatively,cache 704 and processor 702 may be packed together as a “processormodule,” with processor 702 being referred to as the “processor core.”Furthermore, certain embodiments of the present disclosure may notrequire nor include all of the above components. For example, theperipheral devices shown coupled to standard I/O bus 708 may couple tohigh performance I/O bus 706. In addition, in some embodiments, only asingle bus may exist, with the components of hardware system 700 beingcoupled to the single bus. Furthermore, hardware system 700 may includeadditional components, such as additional processors, storage devices,or memories.

An operating system manages and controls the operation of hardwaresystem 700, including the input and output of data to and from softwareapplications (not shown). The operating system provides an interfacebetween the software applications being executed on the system and thehardware components of the system. Any suitable operating system may beused, such as the LINUX Operating System, the Apple Macintosh OperatingSystem, available from Apple Computer Inc. of Cupertino, Calif., UNIXoperating systems, Microsoft® Windows® operating systems, BSD operatingsystems, and the like. Of course, other embodiments are possible. Forexample, the functions described herein may be implemented in firmwareor on an application-specific integrated circuit.

Furthermore, the above-described elements and operations can becomprised of instructions that are stored on non-transitory storagemedia. The instructions can be retrieved and executed by a processingsystem. Some examples of instructions are software, program code, andfirmware. Some examples of non-transitory storage media are memorydevices, tape, disks, integrated circuits, and servers. The instructionsare operational when executed by the processing system to direct theprocessing system to operate in accord with the disclosure. The term“processing system” refers to a single processing device or a group ofinter-operational processing devices. Some examples of processingdevices are integrated circuits and logic circuitry. Those skilled inthe art are familiar with instructions, computers, and storage media.

Miscellaneous

One or more features from any embodiment may be combined with one ormore features of any other embodiment without departing from the scopeof the disclosure.

A recitation of “a”, “an,” or “the” is intended to mean “one or more”unless specifically indicated to the contrary. In addition, it is to beunderstood that functional operations, such as “awarding”, “locating”,“permitting” and the like, are executed by game application logic thataccesses, and/or causes changes to, various data attribute valuesmaintained in a database or other memory.

The present disclosure encompasses all changes, substitutions,variations, alterations, and modifications to the example embodimentsherein that a person having ordinary skill in the art would comprehend.Similarly, where appropriate, the appended claims encompass all changes,substitutions, variations, alterations, and modifications to the exampleembodiments herein that a person having ordinary skill in the art wouldcomprehend.

For example, the methods, game features and game mechanics describedherein may be implemented using hardware components, softwarecomponents, and/or any combination thereof. By way of example, whileembodiments of the present disclosure have been described as operatingin connection with a networking website, various embodiments of thepresent disclosure can be used in connection with any communicationsfacility that supports web applications. Furthermore, in someembodiments the term “web service” and “website” may be usedinterchangeably and additionally may refer to a custom or generalizedAPI on a device, such as a mobile device (e.g., cellular phone, smartphone, personal GPS, personal digital assistance, personal gamingdevice, etc.), that makes API calls directly to a server. Still further,while the embodiments described above operate with business-relatedvirtual objects (such as stores and restaurants), the invention can beapplied to any in-game asset around which a harvest mechanic isimplemented, such as a virtual stove, a plot of land, and the like. Thespecification and drawings are, accordingly, to be regarded in anillustrative rather than a restrictive sense. It will, however, beevident that various modifications and changes may be made thereuntowithout departing from the broader spirit and scope of the disclosure asset forth in the claims and that the disclosure is intended to cover allmodifications and equivalents within the scope of the following claims.

The Abstract of the Disclosure is provided to comply with 37 C.F.R. §1.72(b), requiring an abstract that will allow the reader to quicklyascertain the nature of the technical disclosure. It is submitted withthe understanding that it will not be used to interpret or limit thescope or meaning of the claims. In addition, in the foregoing DetailedDescription, it can be seen that various features are grouped togetherin a single embodiment for the purpose of streamlining the disclosure.This method of disclosure is not to be interpreted as reflecting anintention that the claimed embodiments require more features than areexpressly recited in each claim. Rather, as the following claimsreflect, inventive subject matter lies in less than all features of asingle disclosed embodiment. Thus the following claims are herebyincorporated into the Detailed Description, with each claim standing onits own as a separate embodiment.

What is claimed is:
 1. A system comprising: an online engagementmonitoring module comprising one or more computer processors configuredto monitor online engagements of a plurality of players of a firstonline game, to determine respective engagement parameters for eachplayer; and a recommendation module comprising one or more computingdevices configured to perform automated operations comprising:calculating respective churn probability scores for each of theplurality of players; identifying from the plurality of players a churncandidate by determining that the churn probability score of the churncandidate exceeds a threshold value; and in response to the identifyingof the chum candidate, automatically generating a player-specificmessage that communicates to the churn candidate one or more clues tocomplete an existing in-game task that is to be completed by the churncandidate by performance of gameplay actions within the first onlinegame, and causing delivery of the message to a user device associatedwith the churn candidate.
 2. The system of claim 1, wherein therecommendation module is configured to monitor the online engagements ofthe plurality of players performed during a training period of theonline game.
 3. The system of claim 2, wherein the recommendation moduleis further configured to calculate a respective online engagement scorefor each of the plurality of players, and to base the calculation ofeach churn probability score at least in part on the calculated onlineengagement score for the corresponding player.
 4. The system of claim 3,wherein the recommendation module is configured to calculate eachrespective online engagement score based at least in part on a valuerepresenting how many days the corresponding player played the onlinegame within an assessment time span.
 5. The system of claim 3, whereinthe recommendation module is further configured to: compute a groupaverage of the calculated online engagement scores of the plurality ofplayers; and determine the threshold value for the churn probabilityscore based at least in part on the computed group average.
 6. Thesystem of claim 5, wherein the recommendation module is furtherconfigured to assign a respective weight to each of the onlineengagement scores of the plurality of players, the group average being aweighted group average based at least in part on the respective weightsof the online engagement scores.
 7. The system of claim 6, wherein therecommendation module is configured such that the respective weights ofthe online engagement scores increase in value with an increase inrecency within the training period, the group average being a weightedmoving group average.
 8. The system of claim 7, wherein each of theweights assigned to the respective online engagement scores of theplurality of players is an exponential weight, the group average being aweighted exponential moving group average.
 9. The system of claim 1,wherein the recommendation module is further configured to identify afriend player connected to the churn candidate via a social network tohelp the churn candidate complete the existing task in the online game,and to automatically generate, in response to identifying the otherplayer, a prompt message to the churn candidate for prompting the churncandidate to request help from the identified friend candidate incompleting the existing in-game task.
 10. A method comprising:monitoring online engagements of a plurality of players of a firstonline game, to determine respective engagement parameters for eachplayer; automatically calculating respective chum probability scores foreach of the plurality of players; automatically identifying from theplurality of players a chum candidate based at least in part ondetermining that the churn probability score of the churn candidateexceeds a threshold value; and in an automated operation performed byone or more processors configured to perform the automated operation, inresponse to the identifying of the chum candidate, automaticallygenerating a player-specific message to communicate to the churncandidate one or more clues to completing an existing in-game task thatis to be completed by the chum candidate by performance of gameplayactions within the first online game, and causing delivery of themessage to a user device associated with the churn candidate.
 11. Themethod of claim 10, wherein the monitoring of the online engagements ofthe plurality of players is performed during a training period of theonline game.
 12. The method of claim 11, further comprising calculatinga respective online engagement score for each of the plurality ofplayers, the calculating of each churn probability score being based atleast in part on the calculated online engagement score for thecorresponding player.
 13. The method of claim 12, wherein thecalculating of each respective online engagement score is based at leastin part on a value representing how many days the corresponding playerplayed the online game within an assessment time span.
 14. The method ofclaim 12, further comprising: computing a group average of thecalculated online engagement scores of the plurality of players; andbased at least in part on the computed group average; determining thethreshold value for the chum probability score.
 15. The method of claim14, further comprising assigning a respective weight to each of theonline engagement scores of the plurality of players, the group averagebeing a weighted group average based at least in part on the respectiveweights of the online engagement scores.
 16. The method of claim 15,wherein the respective weights of the online engagement scores increasein value with an increase in recency within the training period, thegroup average being a weighted moving group average.
 17. The method ofclaim 16, wherein each of the weights assigned to the respective onlineengagement scores of the plurality of players is an exponential weight,the group average being a weighted exponential moving group average. 18.The method of claim 1, further comprising identifying a friend playerconnected to the churn candidate via a social network to help the churncandidate complete the existing task in the online game, and, inresponse to identifying the friend player, automatically generating amessage to the churn candidate for prompting the churn candidate torequest help from the identified friend candidate in completing theexisting in-game task.
 19. A non-transitory computer readable storagemedium storing instructions for causing a machine, in response toexecution of the instructions by the machine, to perform operationscomprising: monitoring online engagements of a plurality of players of afirst online game, to determine respective engagement parameters foreach player; automatically calculating respective chum probabilityscores for each of the plurality of players; automatically identifyingfrom the plurality of players a churn candidate based at least in parton determining that the churn probability score of the churn candidateexceeds a threshold value; and in an automated operation performed byone or more processors configured to perform the automated operation, inresponse to the identifying of the chum candidate, automaticallygenerating a player-specific message to communicate to the churncandidate one or more clues to completing an existing in-game task thatis to be completed by e chum candidate by performance of gameplayactions within the first online game, and causing delivery of themessage to a user device associated with the churn candidate.
 20. Thesystem of claim 1, wherein the recommendation module is furtherconfigured to: identify a new in-game task for the churn candidate suchthat the new in-game task is easier than the existing task of the churncandidate in the online game, and send to the churn candidate a promptmessage with respect to the new in-game task.
 21. The method of claim10, further comprising: identifying a new in-game task for the churncandidate such that the new in-game task is easier than the existingtask of the churn candidate in the online game; and sending to the churncandidate a prompt message with respect to the new in-game task.